The (high-cap.) unregulated PSU for chipamps

[Ted205]

the snubber is included in national's datasheet for chipamps -

here

CS7, CS8 act in conjunction with RS1 and RS2 to decouple the large electrolytic capacitors and reduce impedance.

make of that what you will.


its worth playing with the Caps on the power lines at the chip in conjunction with your powersupply.

[Ted205]

has anyone tried these : Suppressors or similar across the bridge diodes ?

They are 100r 100nf snubbers but in one package. Should make things abit easier to retro fit.

[Redshift187]

AndriyOL: What diodes are you using for your rectifier? I've heard that diode snubbers make the sound worse on soft-recovery diodes, like the MUR860s, which I plan on using in my next design.

Ted205: Those suppressors look cool, I'm also interested in any reports by people who have used them.

[Rainwulf]

Originally posted by Ted205
the snubber is included in national's datasheet for chipamps -

here



make of that what you will.


its worth playing with the Caps on the power lines at the chip in conjunction with your powersupply.

Mm thats a good article. Going to sit myself down and have a good read.

[AndriyOL]

Originally posted by Rainwulf
Thank you for testing my design!
I have designed my own amp along the same procedures, however i have very cheap speakers, and i am saving up for some decent ones.


I think the one thing that i am most impressed with is ZERO hum, even from the subwoofer amp (which isnt a gainclone, but its power supply is designed along the same as the one i mentioned above)

I am very glad it worked for you!

Guess I must thank you for your valuable advices in building PSUs.
Almost everyone come to this forum to find such good experience and scientific support. Some come to donate the experience and support. The last ones deserve a gratefulness and respect.
I also don't have superior speakers. I use car speakers with hand made cabinets. I bought some top available from Sony for 75$ for a pair. They are 100W of rated and 420W of max. rms power, 93db/25-33kHz and sound very well as for me.

Originally posted by Redshift187
AndriyOL: What diodes are you using for your rectifier? I've heard that diode snubbers make the sound worse on soft-recovery diodes, like the MUR860s, which I plan on using in my next design.

I use MIC ßU KBPC3506. I don't know who is a manufacturer. Suppose they aren't soft-recovery.
As far as I know MUR860 are old series diodes. Why don't use better ones?

Regards.

[Redshift187]

Originally posted by AndriyOL
As far as I know MUR860 are old series diodes. Why don't use better ones?

Because they have been well tested and liked by many people and are not too expensive. Just because they are old, doesn't mean they aren't good

[AndriyOL]

I have 400VA 2x25VAC toroid which suppose to have 16A of current. Do you know MUR860 are suitable for my toroid? Power ratings requirements of diodes for PSU is calculated for one diode rating or diodes which forms a bridge, thus - 8A*4=32A? I have been thinking about MUR1560 or smth. similar.

Regards.

[mikesnowdon]

I thought people favoured these MUR860's for chipamps basically because the original 47Labs Gaincard used them....

[Redshift187]

Originally posted by AndriyOL
I have 400VA 2x25VAC toroid which suppose to have 16A of current. Do you know MUR860 are suitable for my toroid? Power ratings requirements of diodes for PSU is calculated for one diode rating or diodes which forms a bridge, thus - 8A*4=32A? I have been thinking about MUR1560 or smth. similar.

Regards.

Calculate it based on the individual diode rating. All the diodes are not conducting all the time, and when 2 diodes are conducting, they are in series so both pass all the current. So MUR860 would be 8A. But that's only with a (big) heatsink! They're only rated at 3A without a heatsink.

Originally posted by mikesnowdon
I thought people favoured these MUR860's for chipamps basically because the original 47Labs Gaincard used them....

Well, I do see a lot of "because so-and-so used them they must be the best" around here.

[mikesnowdon]

Well, I do see a lot of "because so-and-so used them they must be the best" around here.

Yeh.